It has previously been attempted to provide an aerogel-containing composite for use as an insulating material. For example WO 97/10187 A1 relates to a composite aerogel material and a method for manufacturing an aerogel containing composite comprising the steps of providing fibers in an amount of from 0.1 to 40%-vol., providing an aerogel particulate material having an average particle diameter smaller than 0.5 mm in an amount of from 5 to 97%-vol., providing a resin binder, mixing the ingredients, and consolidating the ingredients by subjecting the material to hot pressing. This prior art document relates primarily to aerogel composites for electronic purposes taking advantage of low conductivity and low dielectric constant of aerogel. For this particular application thin layers are needed, such as 0.01 to 2 mm, which means that the size of the aerogel particles will influence the mechanical properties of the composite, so the focus of this prior art is to use aerogel particulate material having a very small diameter. No information is provided in the specification regarding the method used to mix the various components of the composite and how this affects the properties of the finished product. In particular, the skilled man is unable to achieve a homogeneous composite based on the information disclosed.
Another example can be found in US 2003/0077438 A1, which also relates to a composite aerogel material and a method for providing a composite aerogel material comprising the steps of providing fibers in an amount of from 0.1 to 40%-vol., providing an aerogel particulate material having an average particle diameter of at least 0.5 mm in an amount of from 5 to 97%-vol., providing a resin binder, mixing the ingredients, and consolidating the ingredients by subjecting the material to hot pressing. The resulting composite is alleged to possess good thermal insulation and good insulation against airborne sound. However, this document provides no information regarding the method used to mix the components of the composite and how this affects the properties of the composite. It does not teach the skilled person how to achieve a high level of homogeneity in the composite.
One of the main problems of previous aerogel containing composites and methods for manufacturing thereof is lack of cohesion and mechanical strength of the composites.